1. Field of the Invention
The present invention relates to an image processing apparatus such as a facsimile apparatus and, more particularly, to an image processing apparatus for performing segmentation processing of input image data, and recording the processed image data to have high quality.
2. Related Background Art
Conventionally, a technique for performing pixel-density conversion of binary image data received by a facsimile apparatus, and segmenting the image data to perform recording, is known. As a related technique, U.S. patent application Ser. No. 599,507 (filing date: Oct. 18, 1990) has been filed.
In a conventional technique, however, since data received at, e.g., 7.7 lines/mm (fine mode) is converted to a double pixel density of 15.4 lines/mm (super fine mode) in the same processing disregarding a character image and a photographic image, when an image including both a character image and a halftone image is received, edges in the character portion are blurred, or gradation of the halftone image cannot be satisfactorily reproduced.
When one line of reception data is recorded as a plurality of segmented lines, reception image data transfer clocks corresponding in number to the plurality of lines must be input in order to perform processing of all the segmented lines, resulting in complex control procedures being required.
In this case, since a data transfer speed of the segmented lines is determined by the speed of the reception image data transfer clocks, when the reception image data transfer clocks are output simultaneously with decode processing, the decode processing takes much time, and the clock speed cannot be increased.
In a conventional apparatus for performing segmentation processing, reception data is stored in an image buffer in advance, and the reception data is then read out from the image buffer to be subjected to image processing. Since a storage operation of the reception data into the image buffer and an image interpolation processing operation are independently performed, it is difficult to realize a high-speed system.
In a conventional apparatus, the image data subjected to segmentation processing is temporarily stored in a line buffer, and is then transferred to a record unit. Therefore, a memory for storing segmented line data is an indispensable component, resulting in increases in cost and size of the apparatus. This problem becomes more serious as the number of segmented lines is increased. Since data must be temporarily stored in the line buffer, it is difficult to realize a high-speed apparatus.